The present invention relates to vehicle air-conditioning systems and in particular to flow control devices.
It is known in the art to provide an air-conditioning system for a vehicle which makes use of blend doors to provide a supply of air of variable temperature to an outlet into the interior of the vehicle. There is usually provided an evaporator for cooling and a heater for heating the air. It is common to situate the evaporator and the heater in the same duct, such that air passes through the evaporator first, after which some or all of it can be heated by passing through the heater.
Furthermore it is known to provide a dual-zone system, whereby two different areas of the vehicle interior can each be supplied with their own supply of variable temperature air. For example, the driver side of the vehicle and the passenger side can each be provided with their own air outlets, the temperature of the air on the driver side being varied by the driver and the temperature of the air on the passenger side being varied by the passenger.
In currently known systems, blend doors are provided inside the air-conditioning ducts, the position of which can be varied to allow different proportions of cooled and warmed air to pass into the vehicle. Such systems suffer from several problems. In general, a separate actuator is required for each blend door, which can be costly and can cause problems with space and access for installation and repair. In order for two blend doors controlling cooled and warmed air for one zone of a vehicle to be controllable by a single dial on the vehicle dashboard, due to the locations of the doors for reasons of space and efficiency, it is often necessary to introduce a gearing system to allow each door to be operated independently. The disadvantages of such a system are that the use of gears introduces additional tolerances into the system whilst at the same time reducing design freedom since both actuation pivots need to be close together.
It would be desirable to provide an arrangement of doors which mitigated some of these problems.
According to the present invention there is provided a flow controller for an air-conditioning system of a vehicle, the flow controller comprising:
a first flow control door, a second flow control door and a first driveshaft running through the first door and coupled to the second door, such that the first door can rotate about the first driveshaft independently thereof and the second door is rotatable by the first driveshaft about the longitudinal axis of the driveshaft;
a third flow control door and a fourth flow control door, wherein each of said doors is rotatable;
a first drive device for said second door and a second drive device for said third door, wherein said first and second drive devices are disposed on a same side of said flow controller;
a first member connecting the second door to the fourth door, such that when the second door rotates, the first member causes the fourth door to rotate;
a second member connecting the first door to the third door, such that when the third door rotates, the second member causes the first door to rotate.
Preferably the third and fourth doors share a common axis.
According to a second aspect of the invention there is provided an air flow control device comprising a first and a second duct, each duct having a respective mouth, and a first and a second door, each door disposed across a respective duct mouth and being pivotable to enable or prevent flow through the associated duct, wherein a member extends from the first door to the second door such that when the first door closes the first duct, the second door opens the second duct and when the first door opens the first duct the second door closes the second duct or that when said first door partly opens the first duct, said second door partly opens the second duct.
Suitably the first door opens and closes about a pivot and the second door opens and closes about a pivot.
Preferably the first and second ducts extend from a common air passage and the common air passage contains an evaporator and the first duct contains a heater core.